To the author's knowledge there exists no established explanation on the mechanism of the erosion of the bricks used in the equipments of bottom casting for producing conventional carbon steel with basic open-hearth furnace, and also with converter. Moreover, while it is generally assumed that the occurence of aluminous sand is very likely due to the erosion of the bricks by molten steel, in particular to the reaction of the reducing SiO2 of fire-clay bricks by Mn of molten steel, whose concentration is closely related to the deoxidizing reaction, the effective method of preventing the sand has not been known.
From the results of the previous investigations the author concluded that the erosion of the bricks is mainly due to the oxides of slaggy matter contained in flowing molten steel, and also the occurence of aluminous sand is likely due to another causes. This paper contains the results of the mathematical-theoretical as well as the experimental studies carried out to prove more clearly the author's conception.